Manufacture of compound mica sheets



(No Model.)

H. s. LUCAS.

MANUFACTURE OF COMPOUND MIOA SHEETS.

Patented Feb. 9, 1886.

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UNITED STATES PATENT OFFICE.

HEMA1\ S. LUCAS, OF CHESTER, MASSACHUSETTS.

MANUFACTURE OF COMPOUND MICA SH EETS.

SPECIFICATION forming part of Letters Patent No. 335,598, dated February 9, 1886. Application filed Xovembor 26, 1883. Serial No. 112,910. (No model.)

To all whom it may concern:

Be it known that I, HEMAN S. Lucas, a citizen of the United States, residing at Chester, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in the Manufacture of Compound Mica Sheets, of which the following is aspecification.

This invention relates to the manufacture of sheets of mica from a number of small sheets, and to improved means for uniting the latter one to the other for said purpose, the object being to provide means for producing larger sheets than can ordinarily be found in the mines; to provide a practical substitute for large sheets of mica, (unbrokem) which, by reason of the rapid exhaustion of the mines, are becoming more and more difficult to obtain, and to provide means for utilizing the great quantity of small blocks or crystals of mica with which the mines abound, and which are of clearer quality than large blocks generally are.

In the drawings forming part of this specification, Figures 2 and 3 are plan views of sheets of mica constructed according to my i11- vention. Fig. 4 is an enlarged sectional view on the line 00 at, Fig. 3. Fig. 1 illustrates a stovedoor having mica sheets therein embodying my improvements. Fig. 5 is a plan of a modification of the metallic strip. Figs. 6 and 7 are sections of plates and uniting-strips in modified form.

In the drawings, A is the frame of the door, and B the central portion thereof, to which the mica sheets are usually secured.

In Fig. 2 is shown a sheet consisting of two smaller sheets, a a. Said sheets are arranged with their meeting edges overlapping, as shown. A strip of copper, brass, or other easy-bending ductile metal, a, is made to en' circle the overlapped ends of said sheets, and the strip 0 and the two ends of the sheets a between the contiguous sides of said strip are perforated to admit the rivets x to be passed through the whole, and the latter are riveted against the opposite exterior sides of the strip, thus securely locking the ends of the sheets a a together.

The sheets of mica shown in the door in Fig.

l are constructed in the manner above described.

By using metal of the nature above mentioned for making the uniting-strip c the compound sheet is easily bent to make it conform to the curve of a door in which it is placed, or for any other purpose-as, for instance, making cylinders for lanterns and other similar objects.

Figs. 3 and 4 illustrate the above-described plan, of making a sheet from four small. sheets, 0 0 0 o. In this construction an additional metal strip, d, is employed, running at right angles to strip 0, and two of the edges of each small sheet 0 are overlapped and fastened between the strips (1 and c in the manner described above relative to the sheet shown in Fig. 2.

It is obvious that the parts of the strip 0 or (Z on the opposite sides of the united ends of the mica sheets a may be united by other means than by the rivets .ras, for instance, making short transverse cuts in the edge of the strip, as at c, and bending portions of the strip between said cuts at right angles to the face thereof, so that said bent portions may perforate the mica and be bent upon the edge of the opposite strip to lock the whole together. I therefore do not limit myself to the use of the rivets x for securing the strips of mica to the ends of the sheets; but any suitable means may be employed.

the manner,-.upou

By the employment of the above-described means for uniting smallsheets of mica to make a large one, the small and nearly worthless blocks of mica which abound in the mines are profitably utilized.

The strips 0 and d are shown in the drawings as having plain surfaces; but they are not necessarily made so; but they may have ornamental surface figures rolled upon them in making them, and thus become ornamental as parts of a compound sheet. (See 0, Fig. 5.) Furthermore, the latter mode, as described, is much less liable to be broken than is a single large sheet of mica, since the metal strip or strips afford more or less protection.

It is obvious that by making the strips 0 and (l proportionately wider the ends of the sheets a. may be abutted rather than overlapped between the strips, and the parts be then se 2. As a new article of manufacture, a comcured as aforesaid, (see c c-,'Eig. 6;) but this pound plate of mica sheets consisting of a modification would involve wider strips, and plurality. of plane sheets of mica" unit-ed at therefore would not be desirable. their proximate edges by strips of flexible r 5 5/ What I claim as my invention is metal covering the joint and secured together,

' 1. As a new article of manufacture, a comsubstantially as described.

pound plate of mica consisting of a plurality of mica sheets with overlapping edges, the lap HEMAN LUCAS being covered by strips of flexible metal and WVitnesses:

10 the strips and sheets united by rivets, snb- J. R. CRISP, stantially as described. HULDA A. BURDIoK. 

